Barut, A. O.; Inomata, A.; and Wilson, R. "Algebraic Treatment of Second Pöschl-Teller, Morse-Rosen, and Eckart Equations."
J. Phys. A: Math. Gen.20, 4083-4096, 1987.Zwillinger,
D. Handbook
of Differential Equations, 3rd ed. Boston, MA: Academic Press, p. 122,
1997.